High Moment Side Shield Design for Area Density Improvement of Perpendicular Magnetic Recording (PMR) Writer

Patent metadata

Field	Value
Publication number	US-2016307586-A1
Application number	US-201615162091-A
Country	US
Kind code	A1
Filing date	May 23, 2016
Priority date	Apr 20, 2015
Publication date	Oct 20, 2016
Grant date	—

Abstract

A PMR writer is disclosed wherein a hot seed layer (HS) made of a 19-24 kilogauss (kG) magnetic material is formed between a gap layer and a 10-16 kG magnetic layer in the side shields, and between the leading gap and a 16-19 kG magnetic layer in the leading shield to improve Hy_grad and Hy_grad_x while maintaining write-ability. The HS is from 10 to 100 nm thick and has a first side facing the write pole with a height of ≦0.15 micron, and a second side facing a main pole flared side that may extend to a full side shield height of ≦0.5 micron. First and second sides may form a continuous curve or a double tapered design where first and second sides have different angles with respect to a center plane. The side shield design described herein is especially beneficial for side gaps of 20-60 nm.

First claim

We claim:

1 . A perpendicular magnetic recording (PMR) writer, comprising:
(a) a main pole with a leading side and a trailing side, and two sides that connect the leading and trailing sides at an air bearing surface (ABS) and proximate to the ABS, the two sides are on each side of a center plane that is orthogonal to the ABS and bisects the main pole; (b) a gap layer that surrounds the main pole at the ABS and is comprised of a write gap that contacts the trailing side, a lead gap adjoining the leading side, and a side gap contacting a side of the main pole on each side of the center plane; and (c) a shield structure including a side shield on each side of the center plane, a leading shield, and a trailing shield comprising;
(1) a first hot seed layer made of a 19-24 kilogauss (kG) magnetic material and with a first side facing the main pole layer wherein a first portion thereof in each side shield contacts the side gap, and a second portion thereof in the leading shield contacts the lead gap;
(2) a second hot seed layer made of a 19-24 kG magnetic material and with a first side facing the trailing side of the main pole and contacting a trailing side of the write gap;
(3) a first magnetic layer made of a 10-16 kG magnetic material that adjoins a side of the first and second portions of the first hot seed layer that face away from the main pole, the first portion of first hot seed layer and a first portion of the first magnetic layer form a composite side shield while the second portion of the first hot seed layer and a second portion of the first magnetic layer form a composite leading shield; and
(4) a second magnetic layer made of a 16-19 kG magnetic material that adjoins a trailing surface and sides of the second hot seed layer thereby forming a composite trailing shield, the first and second magnetic layers form an all wrap around (AWA) shield configuration.

2 . The PMR writer of claim 1 wherein the first hot seed layer has a thickness from about 10 to 100 nm.

3 . The PMR writer of claim 1 wherein the first portion of the first hot seed layer has a full side shield height, or has a height less than that of the first magnetic layer in the composite side shield.

4 . The PMR writer of claim 1 wherein the main pole leading side and trailing side each have a tapered portion with a front end at the ABS, the leading side tapered portion extends a first height (h 1 ) from the ABS, and the trailing side tapered portion extends to a third height from the ABS such that a back end of each tapered portion is a greater distance than the front end from a second plane that is orthogonal to the center plane and the ABS.

5 . The PMR writer of claim 4 wherein the second portion of the first hot seed layer has a side facing the tapered portion of the main pole leading side, and extends to a first end that is less than or equal to h 1 from the ABS, the portion of the magnetic layer in the leading shield that adjoins the second portion of the first hot seed layer extends to the first height from the ABS.

6 . The PMR writer of claim 5 wherein the second portion of the first hot seed layer is further comprised of a section with a side aligned parallel to the second plane and with a front end that adjoins the first end at the first height (h 1 ) and a back end at a second height (h 2 ) from the ABS where h 2 >h 1 .

7 . The PMR writer of claim 6 wherein h 2 is less than about 1 micron.

8 . The PMR writer of claim 1 wherein the first portion of the first hot seed layer is double tapered such that a first side thereof facing a write pole portion of the main pole is formed at a first angle α 1 with respect to the center plane, and a second side of the first portion that faces a flared side of the main pole is formed at a second angle α 2 with respect to the center plane where α 2 >α 1 .

9 . The PMR writer of claim 8 wherein the first side of the hot seed layer first portion extends from the ABS to a height of ≦0.15 micron, and the second side extends from an end of the first side to a side of the side shield structure that is ≦0.5 micron from the ABS.

10 . The PMR writer of claim 1 wherein the write gap has a cross-track width equal to a cross-track width of the second hot seed layer, and greater than a track width of the main pole trailing side.

11 . The PMR writer of claim 1 wherein the side gap has a cross-track width of about 20 to 60 nm.

12 . The PMR writer of claim 1 wherein the second hot seed layer in the composite trailing shield has a first section that is formed substantially parallel to the main pole tapered trailing side, and extends a third height (h 3 ) from the ABS, the second hot seed layer has a second section formed parallel to the second plane and with a front end adjoining the first section of the second hot seed layer at the third height and extends to a fourth height where h 4 >h 3 .

13 . The PMR writer of claim 12 wherein the first section of the second hot seed layer has a first portion at the ABS that is separated from the main pole tapered trailing side by a first cross-track distance, and has a second portion which adjoins a back side of the first portion and is separated from the main pole trailing side by a second cross-track distance greater than the first cross-track distance, the second portion has a back side at the third height.

14 . A method of forming a perpendicular magnetic recording (PMR) writer wherein each of a leading shield, side shields, and a trailing shield is a composite with a hot seed layer made of a 19-24 kilogauss (kG) material adjoining a gap layer around a main pole, comprising:
(a) providing a first magnetic layer made of a 10-16 kG magnetic material that contacts a top surface of the first leading shield layer on each side of an opening which exposes a portion of the first leading shield layer top surface; (b) forming the hot seed layer with a first thickness on each first magnetic layer and on the first leading shield top surface within the opening; (c) performing an ion milling process to determine a height of the hot seed layer from a plane that will become the air bearing surface (ABS); (d) depositing the gap layer having a second thickness on the hot seed layer; (e) depositing the main pole on the gap layer to fill the opening, the main pole has a bottom surface contacting a lead gap portion of the gap layer proximate to the bottom of the opening, and two side surfaces contacting a side gap portion of the gap layer on each side of a center plane that bisects the main pole within the opening; (f) performing a chemical mechanical polish (CMP) process to form a planar main pole top surface that is coplanar with a top surface of each of the gap layer, the hot seed layer, and the first magnetic layer on each side of the center plane, a first portion of the hot seed layer contacts the side gap on each side of the center plane and forms a composite side shield with an adjoining upper portion of the first magnetic layer, and a second portion of the hot seed layer contacts the lead gap and forms a composite leading shield with the first leading shield layer, and lower portions of the first magnetic layer; (g) forming a tapered top surface on the main pole that is a trailing side of the main pole during a write process; (h) forming a stack comprised of a lower write gap and an upper second hot seed layer made of a 19-24 kG magnetic material on the main pole tapered trailing side wherein the stack has a first cross-track width greater than a track width of the main pole tapered trailing side; and (i) depositing a second trailing shield layer made of 16-19 kG magnetic

Assignees

• Headway Tech Inc
• Tdk Corp

Inventors

• Liu Yue
• Yamaguchi Atsushi
• Tang Yuhui
• Lee Jiun-Ting
• Wei Yaguang
• Liu Xiaomin
• Ukita Hideyuki
• Dovek Moris
• Nishiyama Michitaka

Classifications

• G11B5/3116 Primary

  Shaping of layers, poles or gaps for improving the form of the electrical signal transduced, e.g. for shielding, contour effect, equalizing, side flux fringing, cross talk reduction between heads or between heads and information tracks (G11B5/3113, G11B5/245 take precedence) · CPC title

• G11B5/6082

  Design of the air bearing surface · CPC title

• G11B5/1278

  specially adapted for magnetisations perpendicular to the surface of the record carrier · CPC title

• G11B5/315

  Shield layers on both sides of the main pole, e.g. in perpendicular magnetic heads · CPC title

• G11B5/3163

  Fabrication methods or processes specially adapted for a particular head structure, e.g. using base layers for electroplating, using functional layers for masking, using energy or particle beams for shaping the structure or modifying the properties of the basic layers · CPC title